Synopsis

One hot summer day, Naoto Kamino finally musters up the courage to reveal his true feelings for his crush, Manabe Rika. Unfortunately, at the same moment, a young boy named Asumo appears (though he refers to himself as the devil). He plots to kidnap Rika and will stop at nothing to obtain her - but Rika has a little secret of her own, she can transform and obtain magical powers during sex...

half of the sex in this hentai comprises of a loving couple having consensual sex in the missionary position. If that happens to be your fetish you should consider a girlfriend.
In a fantasy hentai with demons and tentacles it's misleading and frustrating.
It isn't even good vanilla sex.
The other half is generic tentacle porn. Describing any aspect of a hentai as generic is about as informative as a forum filled with meme spouting children but its as formulaic as it comes.

Apart from this, there is one thing which grinds my gears about this series. From the start you are baited with a cute
and promiscuous loli angel. It goes so far as to have her captured by the tentacles, and ends it there. Scene over. No other scenes of her, no allusions to anything happening. Nothing.

I feel cheated. EDIT the angel gets a (short) scene in the Jiburiru 3.